GIS Data

Related pages:   FEMA LIDAR  |   Watershed Boundaries |  Nautical Maps 

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Buzzards Bay NEP GIS Data

Note: These data are in ArcViewTM shapefiles, with NAD83 meters coordinates, consistent with MassGIS coverages. The shapefile coverages are all contained in zip files unless otherwise specified. You should right click on the link to save the file to your computer if it is very large, or you can left click to have your browser open the zip file. This is not a complete list of files on our website, and you might wish to use the search button to see if we have a particular coverage.

General Buzzards Bay Data Sets

2023 Buzzards Bay watershed towns Protected Open Space

Buzzards Bay Shellfish DSGA interim 2024 data prepared by the Buzzards Bay NEP (not official, DMF has not yet posted GIS data).

2003 Buzzards Bay NEP’s Filled Wetlands Atlas Volume I sites

Buzzards Bay Salt Marsh Atlas Tidal Restrictions and Phragmites areas
(two coverages included in a 178 kb zip files)

Buzzards Bay Sewered Areas
This is a generalized coverage best for watershed and regional maps. Data coverage for Otis Air Force base is estimated. Prepared January 8, 2015.

Buzzards Bay Study Area

In 2009, as part of the update of the new Buzzards Bay CCMP, the Buzzards Bay NEP adopted a slightly revised “Study Area” definition (jurisdictional interests of the program) shown in the figure below. The southern bay boundary is now consistent with the Massachusetts Ocean Plan area and coincident with the boundary of Massachusetts state waters, and within recently defined state and federal designations for the boundary of Buzzards Bay. The NEP study area totals 684 square miles (=438,142 acres or 1,773 square kilometers). This study area consists of 434 square miles of land (=277,606 acres or 1,123 square kilometers; includes land in both Massachusetts and Rhode Island [6.8 sq miles], freshwater pond area not broken out) and 250 square miles of water in Massachusetts (160,536 acres or 650 sq. kilometers; includes a small portion of areas on nautical charts sometimes labeled Rhode Island Sound in Massachusetts waters). This coverage builds upon earlier coverages. In 2009, two significant updates were made. First the ocean boundary of Buzzards Bay was set to coincide with MCZM’s Massachusetts Ocean Plan Boundary (see https://mass.gov/eea/waste-mgnt-recycling/coasts-and-oceans/mass-ocean-plan/2009-final-ocean-plan.html). Second, USGS better defined the groundwater contribution area in the Plymouth-Carver and Cape Cod aquifers. This GIS coverage, available at: water.usgs.gov/GIS/metadata/usgswrd/XML/ds451_gwcontrib_areas.xml. The USGS data set was smoothed to 100 m intervals and was intersected with earlier Buzzards Bay watershed coverages. Other details about the changing watershed definition is available at on our Buzzards Bay Boundary page.

buzzards Bay Study Area
Click to enlarge

In 2014, we refined the northern boundary, and Cape Cod boundary further to reflect new watershed boundaries defined by the Massachusetts Estuaries Project in those areas. Download the zipped shapefile: bbnep_studyarea2014final.zip. For comparison, we also provide the Buzzards Bay 2006 watershed major basin boundary. (zipped GIS shape file) we had previously used.

Buzzards Bay Subbasins

This 2017 subbasin coverage is currently being used by the Buzzards Bay NEP: BBNEP_SUBBASINS_2017.zip. We are also making available this July 2012 coverage. Although the Buzzards Bay subbasins are superseded, the boundaries in this file might have been used in some past studies, and it also contains subbasins for all of Southeastern Massachusetts: bbnep_semass-subbasins_july2012.zip . For comparison, here is the 2009 sub-basin boundaries (zipped GIS shape file) we posted previously.

In 2009, the Buzzards Bay NEP updated it subbasin coverage to make it consistent with our major basin boundary and the latest GIS data and subwatershed delineations (including groundwater boundaries) from the MEP, DEP, and USGS. MEP defined boundaries were given precedence where inconsistencies existed between data sets. More information about these coverages can be found on our Nitrogen Management origins page. More information about these coverages can be found on our Nitrogen Management origins page and our Buzzards Bay watershed boundary page.

Specialized Coverages

New Bedford Harbor Bathymetry
New Bedford Harbor Bathymetry
(color coded map, 496 kb JPG)

New Bedford Harbor Bathymetry GIS Shapefiles
This is a 565 kb zip file that opens into the three necessary ArcView files. Depths as NGVD29 feet at MLLW (mean lower low water). This data is shown in the image to the right.

Links to Other Data Download Sites with Buzzards Bay Coverages

Great federal site for LiDAR data: NOAA Data Access

Massachusetts Ocean Resource Information System

NOAA Nautical Chart Viewer and downloader including GIS format

Historical Aerial Photos: Earth explorer at USGS
Install Google Earth With Google earth, you can select aerials from different dates as the base map.

Converting xy coordinates into a shapefile

Step 1. Create an xy data base file in Excel. The file should look like this:

X Y ID field1 field2
373.2330 603.3111 marker1 catchbasin treated
373.2330 603.3111 marker2 catchbasin untreated

[Note: the IDs can all be zero, or a discreet numeric or string identifier. Your “x value” is longitude or easting. For decimal degrees, don’t forget to add a negative sign for our hemisphere.]

Step 2. Export the file as a Dbase IV file.
[A quirk of Excel is that after you modify the database, you may have to close the database and reopen it before exporting to ensure the dbf file looks like the xls file. It is a good idea to format numeric cells with the preferred number of significant digits and format non-numeric fields as text to avoid other hitches.

Step 3. Open ArcView, click on tables, and ADD Table. Add the table from the directory where you saved it

Step 4: Click on View-Add Event Theme. ArcView may default to the dbf table you just added.

Step 5: use a script or tool like Xtools ® to convert points into a polygon if desired

Step 6: If you entered UTM data from a quad sheet, convert the data to Mass State plane 1983 meters.

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